Check declared schema locations for external resources

internal/validate/schema_locations.go

@@ -0,0 +1,91 @@
+package validate
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/santhosh-tekuri/jsonschema/v6"
+)
+
+// These schema-bearing positions mirror the inherited subschema tables in
+// jsonschema/v6 v6.0.2 draft.go. Annotation objects are deliberately excluded.
+func checkSchemaLocations(ctx context.Context, compiler *jsonschema.Compiler, resourceURL string, document any, pointer string, compiled *jsonschema.Schema) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	object, ok := document.(map[string]any)
+	if !ok {
+		return nil
+	}
+	version := compiled.DraftVersion
+	mapKeys := []string{"definitions", "properties", "patternProperties", "dependencies"}
+	singleKeys := []string{"not", "additionalProperties", "items", "additionalItems"}
+	arrayKeys := []string{"allOf", "anyOf", "oneOf", "items"}
+	if version >= 6 {
+		singleKeys = append(singleKeys, "propertyNames", "contains")
+	}
+	if version >= 7 {
+		singleKeys = append(singleKeys, "if", "then", "else")
+	}
+	if version >= 2019 {
+		mapKeys = append(mapKeys, "$defs", "dependentSchemas")
+		singleKeys = append(singleKeys, "unevaluatedProperties", "unevaluatedItems", "contentSchema")
+	}
+	if version >= 2020 {
+		arrayKeys = append(arrayKeys, "prefixItems")
+	}
+	visit := func(value any, segments ...string) error {
+		switch value.(type) {
+		case map[string]any, bool:
+		default:
+			return nil
+		}
+		childPointer := pointer
+		for _, segment := range segments {
+			childPointer += "/" + strings.ReplaceAll(strings.ReplaceAll(segment, "~", "~0"), "/", "~1")
+		}
+		parsed, err := url.Parse(resourceURL)
+		if err != nil {
+			return err
+		}
+		parsed.Fragment = childPointer
+		child, err := compileJSONSchema(ctx, parsed.String(), compiler.Compile)
+		if err != nil {
+			return fmt.Errorf("compile declared schema %q: %w", childPointer, err)
+		}
+		return checkSchemaLocations(ctx, compiler, resourceURL, value, childPointer, child)
+	}
+	for _, key := range mapKeys {
+		entries, ok := object[key].(map[string]any)
+		if !ok {
+			continue
+		}
+		for name, value := range entries {
+			if err := visit(value, key, name); err != nil {
+				return err
+			}
+		}
+	}
+	for _, key := range singleKeys {
+		if value, ok := object[key]; ok {
+			if err := visit(value, key); err != nil {
+				return err
+			}
+		}
+	}
+	for _, key := range arrayKeys {
+		entries, ok := object[key].([]any)
+		if !ok {
+			continue
+		}
+		for i, value := range entries {
+			if err := visit(value, key, strconv.Itoa(i)); err != nil {
+				return err
+			}
+		}
+	}
+	return ctx.Err()
+}